1. Field of the Disclosed Embodiments
The disclosure relates to test circuits and more specifically to a system and method for performing a test on analog to digital and digital to analog circuits.
2. Introduction
In many integrated circuits (ICs), both an Analog to Digital Converter (ADC) and Digital to Analog Converters (DAC) are present, to allow digital signal processing (DSP) of analog input signals and generation of an analog result. This is often called a “mixed signal” IC.
Testing of embedded analog/mixed-signal cores is considered a difficult problem in System on Chip (SoC) IC testing. In general, various design-for-test (DFT) schemes are used to access the embedded analog blocks such as digital-to-analog converters (DAC) and analog-to-digital converters (DAC), while the testing is performed by specialized hardware such as mixed-signal automatic test equipment (ATE) or an IC tester. The difficulty in testing embedded analog/mixed signal blocks is primarily due to difficulties in applying the test stimuli to the analog blocks and observing the response of the analog blocks for evaluation. This difficulty is further enhanced due to the fact that these blocks require an analog signal as test input or their response output is an analog signal. Thus, a simple binary comparison cannot be conducted in testing.